A relatively recent major development in farm equipment is a baler which is moved along a windrow of fodder to roll a large fodder bale which is left on the ground. Such bales may be five or six feet in diameter and weigh several tons. It has been found that the tendency of such bales to disintegrate is greatly reduced if they are wrapped with twine, which may conveniently be guided into the front of the baling chamber by a twine arm (usually a tube). As the twine arm swings across the front of the baling chamber the twine is wrapped spirally about the bale.
A variety of devices have been developed for controlling in the dispensing of the twine by the twine tube. Typical devices known to applicants or their attorney are disclosed in U.S. Pat. Nos. 3,884,138, 3,913,473, 3,988,977, 4,022,120, 4,024,804, and 4,072,095.
The above prior art patents have dealt with a number of different phases of bale twine wrapping. Among the more important ones are means for clamping a short, loose end of twine hanging from the end of the twine arm; withdrawing from the twine arm a predetermined amount of twine before wrapping of the twine around the bale commences, and then automatically releasing the twine hanging from the arm to start the wrapping of a bale; and severing the twine when a bale is completely wrapped coupled with clamping of the short loose end left between the twine cutter and the twine arm.